This invention relates to a device for setting operational conditions of respective components included in a combination weighing machine when it is operated.
As shown, for example, in U.S. Pat. No. 4,664,200, a combination weighing machine generally includes a plurality of weigh hoppers, a plurality of feed hoppers for feeding product to the weigh hoppers, a plurality of feed conveyers for feeding product to the feed hoppers, a collection chute for collecting a batch of product discharged from some of the weigh hoppers for delivery to a packing machine, and a control unit for controlling these components.
The control unit is adapted to execute a combination operation for combining weight signals from the weigh hoppers in various fashions, calculating total weights of these combinations and selecting a combination having a total weight equal or nearest to a predetermined target weight within a predetermined allowable range of weight, and a discharge operation for discharging product from those weigh hoppers relating to the selected combination to a collection chute for delivery to the packing machine. The control unit also executes a feed operation for feeding product to the emptied weigh hoppers from corresponding feed hoppers and then operating corresponding feed conveyers to feed product to the emptied feed hoppers. The control unit repeats these operations in a predetermined time sequence at a preset frequency to successively deliver batches of product to the packing machine.
For operating such a combination weighing machine, it is necessary to previously provide the control unit with various operational conditions or data of operational parameters. The operational parameters include a target weight value and upper and lower limits of an allowable range of weight. They also include a speed of operation indicative of the number of batches of product delivered every minute, vibration amplitude and duration of each feed conveyer determinative of the amount of product fed to the corresponding feed hopper, a feed hopper gate opening time sufficient for discharging the whole content of each feed hopper into the corresponding weigh hopper, a weigh hopper gate opening time sufficient for discharging the whole content of each weigh hopper into the collection chute, and a stabilization time necessary for stabilizing the weight signal from each weigh unit. In the prior art, as described, for example, in the Japanese patent opening gazette No. 62-103524, these data are suitably collected and stored in a memory for every product name or target weight under a specific program number and, before starting operation of the combination weighing machine, they are read out from the memory and set in the control unit by inputting the corresponding program number.
In the prior art device, however, such work of previously collecting and storing the data of many operational parameters for every product name or target weight is very time-consuming and, moreover, it is difficult for unskilled persons since substantial experience is required to select the parameter values suitable for a desired operational condition of the machine.